Method and means for controlling the operation of steam engines



March 16, 1937. v. z. CARACRISTI 2,073,921

METHOD AND MEANS FOR CONTROLLING THE OPERATION OF STEAM ENGINES FiledJuly 24, 1934 4 Sheets-Sheet l INVENTOR M ATTORN March 16, 1937. v. z.CARACRISTI ,9

METHOD AND MEANS FOR CONTROLLING THE OPERATION OF STEAM ENGINES FiledJuly 24," 1934- 4 Sheets-Sheet 2 X SA TUEATED $754M 0 2 4 6 a 10 I2 /4 6I8 P/570/V SPEED Hum/P: 0F Fit-7 P5? MM.

6 PEI? m ormmmv P/sm/v Pl/Zl 1095 33 5 252 121 ag ap 3 3 INVENTOR MA'I'I'ORN I Z [I I f I I Vuyzmzu ara raw 1 BY b a March 16, 1937.

v. z. CARACRISTI 2,073,921

METHOD AND MEANS FOR CONTROLLING THE OPERATION OF STEAM ENGINES FiledJuly 24, 1934 4 Sheets-Sheet 3 INVENTOR March'16, 1937. v. z. CARACRISTI2,073,921

METHOD AND MEANS FOR CONTROLLING THE OPERATION OF STEAM ENGINES FiledJuly 24, 1934 4 Sheets-Sheet 4 INVENTOR.

Patented Mar. 16, 1937 PATENT OFF-ICE METHOD AND MEANS FOR CONTROLLKNGTHE OPERATION OF STEAM ENGINES Virginius Z. Caracristi, Bronxville, N.Y.

Application July 24,

8 Claims.

The invention disclosed in this application relates generally to amethod of and an apparatus for aiding an operator of a steam engine, andmore particularly of a steam locomotive, to control said engine in amanner which will insure more satisfactory and eflicient operationthereof by means of a single index indicating the performance in termsof percent of the maximum permissible piston pull or effort.

The present application is a continuation in part of my applicationSerial No. 441,476, filed April 4, 1930, for a Method and means forcontrolling the operation of steam engines.

It is well known to those skilled in the art of reciprocating steamengineering that there are three important and variable factors whichcollectively determine the degree of relative efficiency with which theengine is operating or the percentage of maximum available piston pull,which is being developed at a particular speed. These factors are pistonspeed, percentage of cut-off, and steam pressure. Furthermore, thesefactors bear a certain very definite relation with respect to each otherwhich will be more particularly hereinafter pointed out and discussed.

It is therefore the general object and purpose of this invention toprovide an apparatus for proper consideration of the variable factors ofpiston speed, steam pressure and percentage of cut-off, so that theindividual fluctuations thereof may be suitably translated or convertedinto movements, and in utilizing the effect of these movements tooperate suitable indicating apparatus arranged to apprise the engineerof the eifective resultant of such variable factors as evidenced in thepercentage of maximum available piston pull being developed or therelative degree of efilciency of operation of the engine under existingconditions of load.

It may be noted here that according to the principle of the presentinvention there is no correlation of any two of the variable factors, assuch, but that, to the contrary, all three factors, viz, pressure,piston speed and position of the control valve, combine to producesingle result or effect which is made known to the engineer by anindicating apparatus, and that in this result the factor of pistonspeed-is not to be interpreted as or confused with surface speed. Itwill be appreciated that in a locomotive or other traveling engine, thesurfaceor travel speed is dependent upon the relative size of thedriving wheels and the fixed piston stro'ke. In my invention as hereindisclosed, piston speed is the essential 55 factor as to speed, neitherthe size of the driving 1934, Serial No. 736,654.

wheels nor the resultant surface speed being a desideratum in thatresult. in the following specification I have referred by way of exampleto a speedometer as a suitable instrumentality for translating thevariations in the piston speed factor, it is to be understood that suchinstrument is used because of its convenience for this specific purposeand that it is so used without having reference to its common andwell-known function as a surface speed indicating device.

With these and other objects in view the invention comprises certain newand improved features in the method of and apparatus for generallyimproving and correcting existing errors in the conditions under whichan engine is operating which will be fully apparent from reading thefollowing specification when considered in connection with theaccompanying drawings, wherein:-

Figure 1 is a diagrammatic view illustrating one form of my apparatusfor effectively interlocking the variable factors of speed, cut-off andsteam pressure, and giving each its due consideration and converting theresulting effect of such into a single force which is applied to actuatean indicating element, the several parts being shown in the relativepositions they occupy when the locomotive is at rest;

Fig. 2 is an elevational view on a larger scale of the indicatingapparatus, parts being broken away;

Fig. Bis a chart showing the relation of variations in piston speeds tohorse power output as expressed in percent of maximum effective pistonpull and percent of maximum available horse power output;

Fig. 4 is a view of a section of therecord tape having the comparativerecords of steam chest pressure percent of maximum horse power output,and driving speed marked thereon during a run of the locomotive;

Fig. 5 is a partial sectional view, more or'less diagrammatical incharacter, of the indicating apparatus, showing the transmission foroperating the modifying cam and the index hands, and also showing theparts for producing on the tape the lines denoting speed curve andpercent of maximum piston pull;

Fig. 6 is a detailed view on a larger scale of the modifying cam; and

Fig. 7 is a view similar to Fig. 1, but without the tape, and showingthe relative positions of the parts of the apparatus when the locomotiveis traveling at the rate of sixty miles per hour.

Therefore, whereas Before referring specifically to the featurescharacterizing my novel method and apparatus it is well to considerbriefly the various factors which tend to complicate the problem ofsteam 5 engine operation and control, particularly steam locomotives.There are various factors tending to retard or oppose the operation ofan engine, or locomotive, over which the operator has little or nocontrol. These factors include journal friction, variation in attachedload, air resistance, slippage between the wheels and the rails, andothers. To overcome the resultant efiect of any or all of those factorswhich may be pres= ent in a given case, the engine operator has at hiscontrol a motive fluid in the form of steam under pressure; means forconverting the energy of the steam into mechanical forces applied toimpart motion to the engine, and controlinstrumentalities forcontrolling the rate at which the conversion of energy takes place.Obviously, the rate of conversion is variable within the very definitelimits fixed bythe boiler capacity and engine ratin and therefore theimportant problem from a practical standpointis to manipulate thecontrol instrumentalities in a manner such as to insure relatively highefliciency or economy in operation or to develop the maximum possiblehorse power output under prevailing conditions, as occasion demands.

The principal control instrumentality utilized in conventionallocomotive control is.the cutofl valve as adjusted through operation ofthe reverse lever. The valve is manipulated to vary the point ofcut-off, that is, the period of steam admission to the engine cylinder.The amount and pressure of steam admitted to the cylinder of anengine'at each stroke determines the work that the cylinder produces,and this in turn determines the available piston pull or turning efiortcapable of being produced. However, the amount of steam which may entera cylinder at each stroke (for a given point of cut-off) decreases withincrease in speed of operation of the engine. Bearing in mind that horsepower is the rate of doing work, it is at once apparent that speed ofoperation has an important bearing upon the operating characteristics ofan engine when considered either from a standpoint of relativeefiiciency or of maximum horse power that may be developed. Experiencehas shown that maximum turning effort or effective piston pull can berealized only through the range of piston speeds at which it is possibleto maintain the mean or effective 55 steam pressure within the cylinderat a maximum value which, for all practical purposes, is approximately0.8 of the existing boiler pressure. Beyond this range of speeds theperiod of admission must be shortened to maintain steam consumptionwithin the capacity of the boiler, and in this connection experience hasalso shown that if the highest efliciency is desired the cutoff valvemust be operated in a manner to emciently use the steam at the maximumrate at 65 which the boiler can supply it.

In my apparatus, as will hereinafter appear,

100% is used to represent the maximum available horse power a locomotiveis capable of constantly developing under correct position of cutoff forany speed at which the locomotive may be operating. This 100%, used as astandard,

may be described as a variable constant, the

variables being speed, boiler capacity, steam pressure and position ofcut-off. Any combi- 75 nation of these variables when in correctrelation to each other is expressed by the stan of 100%. Hereinafter, Ishow by mathematical example why it is that the relationship oflocomotive travel to its piston speed is constant for any speed of thelocomotive. In the description of the particular example given it isstated" This relationship of 226,195+ to 56 remains constant for anyspeed. Obviously this is true for all points of the cut-off, since thecut-ofi controls the admission of steam only and does not change theconstant relationship between locomotive travel and piston speed.

With this 100% as a standard, my apparatus is devised, on the one hand,to show when and to what extent the locomotive is doing more work' thanthe standard establishes for prevaiiing speed, in which event theengineer can correct the over-plus by shortening the cut-ofi; and

on the other hand, to' show when and to what extent the locomotive isdoing less work than the standard establishes for prevailing speed, inwhich event the engineer can correct underperformance by lengthening thecut-off.

These relations between speed and horse power, and between speed andeffective turning effort or piston pull are graphically shown in Fig. 3.In the chart on which these curves have been plotted the horizontalordinates denote piston speed in hundreds of feet per minute, whereasthe vertical ordinates denote percentage of maximum effective pistonpull and percentage of maximum available horse power, respectively.These curves and the variations which they depict are familiar to thoseversed in the art pertaining to reciprocating steam engineering, andinformation concerning the manner in which they are plotted may be foundin any recognized text-book on the subject, such as W. E. Dalbys SteamPower (see pages 439 and 448).

Referring now in particular to Fig. 3, it will be seen that I haveplotted two illustrative curves indicated by the reference characters 6and l and which show the effect of piston speed on available pistonpull, the curve 8 showing these effects when saturated steam is used,and the other curve 1 showing the similar effects when superheated steamis used. Similarly, I have plotted two illustrative curves 8 and 9 whichshow the relation of piston speed to indicate horse power and of thesetwo curves the curve 8 shows the relation when saturated steam is used,

- while the curve 9 shows a similar relation when superheated steam isused. All of' these curves presume correct steam pressure control.

The curves 6 and 'i of Fig. 3 show that tractive force is independent ofspeed up to piston speeds approximating 250 feet per minute. Beyond thisspeed it is impossible to maintain maximum effective steam chestpressure because of the inability under higher piston speeds to maintaina maximum effective or constant value in the boiler supply, in additionas well to the effect of back pressure necessarily incident to highpiston speeds. In order to maintain the mean effective pressure at ornear a maximum constant value, the period of admission must be shortenedat hiihgr piston speeds, as has previously been indica e Curves 8 and 9of Fig. 3 show that the maximum available horse power output increaseswith piston speed up to approximately 1000 feet per minute andthereafter falls ofi sharply. The actual value of the horse power outputalso increases as the point of cut-off is increased but the speed atwhich maximum horse power occurs 2,073,921 for different points ofcut-off, remains substantially constant at 1000 feet per minute. Thus itis apparent that the maximum'horse power output as indicated byeither ofthe curves 6 or 9, bears a direct relationship to the possible tractlveeffort as influenced by piston speed, the available steam pressure andpoint of cut-off. Therefore, in order to insure the development ofmaximum horse power under existing conditions of steam pressure andpiston speed, it is necessary for the engineer to correct the cut-offpositions in a manner to cause the variations in effective piston pullor tractive effort to follow the curves 6 or I, as the case may be.

It is at once apparent that, in the absence of some instrumentalitywhich will indicate to'the operator when and to what extent the actualvalues of these variable factors deviate from the theoretical propervalues therefor, the operator must rely on his ability to properlyinterpret the operating characteristizs of the engine to know when andto what extent to vary the cut-off. Naturally, this is a very uncertainbasis of control and even in the case of enginemen with long years ofoperating experience, the manipulation of the throttle and cut-off is toa large extent a matter of guess-work.

With these facts in mind I have devised an apparatus for properlyindicating by a single index the effect produced through the variationsin steam pressure, tractive force as influenced by speed, and cut-off,by instrumentalities which, in effect, combine these several forces intoa resultant, the effective variations in which are visibly indicated tothe engineman in terms of percent of maximum effective piston pull beingdeveloped by the locomotive at a particular speed, so that he may knowat all times what relation the actual operating conditions of the enginebear to the theoretically proper conditions.

It will, of course, be understood as this description proceeds, thatinsofar as the mechanical features of my present disclosure areconcerned, the drawings are purely illustrative, and merely suggestiveof the different functional operations whereby the modifying factorsgoverning the proper steam chest pressure and cut-01f position asaffected by piston speed may be translated and converted into indicativeterms comprehensible to the engineer, so that he may make the propercorrections in the position of the reverse lever as may be required forthe current piston speed.

Referring now to Fig. 1 of the drawings, wherein I have illustrated oneembodiment of the apparatus by which I may provide an indication of theresultant effect of the several variations hereinbefore referred to, Kdesignates generally a composite indicating instrumentality which I willrefer to more particularly hereinafter. This instrument K is operativelyassociated with three elements I0, I8, and 23, which are arranged tomove by direct means in response to, and to reflect variations inchanges in the position of cutoff, steam pressure and piston speed,respectively. The element I0 is shown as a rod suitably mounted forreciprocation in response to changes in the position of the cut-offvalve of the engine. This rod is connected up with the conventionalreverse lever mechanism of the locomotive on which my apparatus is to bemounted and in a manner such that, as the cut-off is moved to shortenthe period of admission, the rod is raised or lifted by the tension ofthe pull spring Ma.

The connection between said rod I0 and the reverse mechanism of thelocomotive may be accomplished in any suitable manner. For purposes ofillustration I have shown the conventional reverse lever 50 connected bya link 5| with a bell crank lever 52, the latter being secured to across shaft 53 which in conventional locomotive practice is termed thevalve or tumblingshaft,and functions through the instrumentality of saidbell crank 52, to operate the usual valve gear of the locomotive engine.Also secured to the tumbling shaft 53 is an arm 54 which is connected bylink 55 to a lever 56 suitably mounted for rotative or turning movementupon a shaft 5'! carried by a frame member 58. Freely mounted forrotative movement upon shaft 57 is an arm 59, with which the rod I0 ispivotally connected by pin 60. In order to properly position the arm 59,I provide an abutment 6I against which a lug 62 carried by the arm 59 isnormally urged by the action of spring Illa on rod II]. The lug 62 isarranged to project laterally beyond the abutment SI, as shown, andagainst this lateral extension of the lug 62 is engaged a lug'63 carriedby the arm 56. Under this arrangement, when the reverse lever 50 isthrown forward from its central or neutral position, in which it isshown in Fig. 1, the lug 63 through its engagement with the lug 62,rocks the arm 59 in a counterclockwise direction on the shaft 57,whereupon the rod I0 is shifted downwardly. When the lever 50 isreturned toward its central position, the arm 59 brings the rod I0upwardly in a clockwise direction until the lever 50 is in neutralposition, at which time the lug 62 is in engagement with the abutment6|.

The above describes the operation of this apparatus when the locomotiveis moving forward. Ifit is in reverse motion, indicator 2'! will move inthe reverse direction to that described above, but the effects ofvariations of boiler pressure and of piston speed will be the same asabove described.

The element I8 may also take the form of a rod, and is shown connectedto a piston I6 arranged for reciprocation within a cylinder I5, theinterior of which is in communication with the steam chest of the engine(not shown) by means of the conduit I5a. A spring member I! isinterposed between the piston I6 and one end of the cylinder so as toresist the tendency of the steam pressure acting on the under side ofthe piston to move the piston upwardly. Thus, as the steam pressurevaries, the spring I7 will yield more or less to permit the piston I6 tomove in response to such variations and these pressure variations arethereby reflected in the position of the rod I8.

It may be remarked here that by steam chest pressure, I mean theconstant pressure as measured at the closest point to the cylinder wherethe pressure is not affected by the piston action or by the cut-offeffect and is beyond the point at which frictional losses through pipescan occur. The device I5 should not be connected to the cylinder where afluctuating pressure condition would result and thereby affect piston I6by such fluctuating steam pressure. Steam pressure being boiler pressureless only friction losses through superheater units, etc.,

it follows that the device I5 should be connected to the steam chestproper where the position of the piston I6 will remain constant withboiler pressure less steam friction losses.

The element 23, also shown in the form of a rod, is arranged toreciprocate in response to changes in piston speed of the engine. Tothis end, I may provide an operative connection between said element andan eccentric cam member 22 mounted for actuation in.response to changesin piston speed through a inedium which will presently be described. Asshown, the rod 23 is provided with a roller 23' which is constantlymaintained in engagement with the periphery of the cam 22 by a springI23 so that as the cam 22 shifts about its axis 22' in response tochange in piston speed, the rod 23 will be shifted sure decreases.

rectilinearly up and down, to an extent dependent upon the degree ofangular movement of the cam 22. Furthermore, the cam 22 is designed sothat the roller 23 in following the cam contour, will impart to the rod23 a motion corresponding to the variations in the percent of maximumpiston pull that it is possible to develop under given conditions ofpiston speed and cut-oil, as illustrated by the curves 6 or I in Fig. 3.In other words, the periphery or contour of the eccentric cam is plottedso as to move the roller 23' from a position corresponding to that ofthe base line 5 of Fig. 3 at zero speed a distance dependent upon thespeed of the piston,

and which distance varies in accordance with the curves 6 or i of Fig.3. Thus, any instant position of the rod 23 will indicate the percent ofmaximum piston pull being developed at the prevailing speed.

In view of the fact that thepiston speed at which maximum piston pull isdeveloped is practically the same for all positions of cut-off that areproper" when considered in terms of the prevailing piston speed so as touse steam at the maximum rate permitted by the boiler capacity,

the position of rod 23, if its movements are combined with the movementsof rods l0 and I8 to move a single movable indicating element may bemade to indicate by the position of the indicating element the percentof maximum piston pull being developed. For this purpose I employcertain mechanical means for translating or converting variations in theposition of cut-ofi, pressure of steam, and piston speed as evidenced inthe movements of the responsive elements l0, l8, and 23, respectively,into movement of the single indicating element or hand 21 which ismovable along the face of a suitable'scale 28 on instrument K,-calibrated as hereinafter described in percent of maximum piston pull,to apprise the engineer of the actual and instantaneous combined eifectof said responsive elements upon the output of the engine. As previouslyexplained, the rod H3 is controlled in its movements by the movements ofthe reverse lever; being moved upward as the reverse lever is moved inadirection to shorten the cut-off and downward as the reverse lever ismoved in a direction to lengthen the cut-off. The rod I8 is controlledin its movements by variations in steam pressure; being moved upward assteam pressure increases and downward as such pres- The rod 23 iscontrolled in its movements by the movements of cam 22 in response tochanges in piston speed; being moved upward for increase in speed anddownward as such speed diminishes. According to the operative principleof the apparatus of my invention, a downward movement is given to rod l0when the cut-oil is lengthened by moving the reverse lever from neutral,an upward movement is given to rod l8 when steam pressure increases dueto the action of increasing steam pressure on piston l8,

and an upward movement is given to rod 23 when piston speed increasesdue to the action of the eccentric cam 22 on the rod 23. Now, by each ofthese movements-downward movement of rod I0, upwardmovement of rod l8and upward movement of rod 23-the indicating hand 21 is moved along thescale 26 in the same direction, which in the present embodiment hereinillustrated is counterclockwise as will presently appear. The

indicating hand 27 is moved in an opposite direction, that is to say, ina clockwise direction, when the cut-ofi is shortened, or when steampressure is decreasing, or when piston speed is decreasing.

If, therefore, the indicating hand 27 has been or is being movedcounterclockwise by increasing steam pressure or by increasing pistonspeed, it may be moved in an opposite direction or clockwise byshortening the cut-ofi; and also, if the hand has been, or is beingmoved clockwise by decreasing steam pressure or by decreasing pistonspeed, it may be moved counterclockwise by lengthening the cut-ofi.

The mechanism by means of which from the movements of the rod elementsl0, l8, and 23 the indicating hand 21 is moved along the scale 28,comprises a system of levers arranged to integrate the movements of theindividual elements l0, l8, and 23 with respect to the efiect suchmovements (or the variations in the particular factor they reflect) hason the operation of the engine as expressed in percent of maximum pistonpull being developed. Thus, considering that lengthening the cut-oil hasa similar efiect on the operation of the engine as does raising theefiective pressure within predetermined speed range and vice verse, Iconnect the rods ID and i8 to my system of levers so that countermovements in said rods will causea corresponding eiiect in the elementl2 which is moved in response to variations in the .movernents ofelements it, l8, and 23 to control the operation of the singleindicating element or hand 21. Likewise, as increases in speed demanddecreasing the cut-off, the rod 23 is arranged to produce in the motionof the element l2 and hence in the controlled single indicating elementor hand 27, which parts alike respond to variations in the resultantbetween elements IQ and (8, an opposite effect, that is to say, the rod23 is arranged so that by its movements the element l2 may be givenmovements counter to the movements which it receives from the rod I0.With an arrangement in which the movements of element 12 derived fromrods 23 and 18, are counter to the movements which are derived from therod 10, if the system of connecting levers provides for the movement ofelement l2 by rod ID a corresponding or greater movement than isobtained by the resultant movements from rods I81and 23,

then the element l2 by the rod Ill can be moved in a counter directionfrom the position to which it has been moved by the combined movementsof rods I8 and 23. Thus, I connect the upper end.

of the rod 23 to one end of the lever 20 by means of a pin and slotconnection 24, and to the opposite end of said lever I connect the rodl8 by a similar pin and slot connection l9. The lever2ll is pivotedintermediate its ends upon one end 2! of a link I4, said link beingmounted for-rectilinear reciprocation in asuitable guide Ma. The upperend of the link I4 is pivotally connected as at I 3 to an intermediatepart of a second lever H. One end of this lever H is connected to-therod I0 by a pin and slot connection l0 so as to be moved by said rodupwardly as the cut-off is shortened, and downwardly as the cut-off islengthened, thus corresponding to the upward and downward movements ofthat end of the lever 20 which is connected to the' rod 18, in responseto increases and decreases, respectively, in the steam pressure. isconnected by a pin and slot connection at 2| to rod I2 mounted forreciprocation, and mechanically connected by means of a rack 30 formedthereon, to a gear 3! carried by the shaft A of the single indicatingelement or hand 21 (see Fig. 5) of the instrument K, so as to operatethe element 21 in response to variations in the position of the rod I2.In this system of levers, in which the lever H is rockable upon thefulcrum point l3 by the rod and in which said fulcrum point is supportedupon the lever '20 for raising and lowering movements accordingly asrods "3 and 23 are raised and lowered, the leverage relation is suchthat the rocking movement of lever II in any position of its fulcrumpoint l3, has a dominating effect in the combined leverage systemwhereby to move the element l2 and hence the indicating hand 21 in acounter direction a distance corresponding to any movement that can begiven to said element 12 and hand 21 by the system resultant movementsof rods l8 and 23. Thus it will be apparent that variations in therelative positions of the rods l0, l8, and 23, reflecting fluctuationsin cut-off, steam pressure and piston pull as influenced by pistonspeed, respectively, are resolved by the system of levers including theelements 20, I4, H, and I2 into movement of the hand 27 which, whenassociated with a suitable scale 28 calibrated in percent of maximumpiston pull, will indicate to the engineer the relative percent ofmaximum piston pull being developed under existing conditions of pistonspeed, steam pressure and cut-01f.

Referring more particularly to the instrument K, the same comprises asuitable speed indicating dial 25 preferably calibrated in miles perhour, and cooperating therewith is a hand or pointer 26 carried by ahollow shaft or sleeve B which in turn is mounted upon the shaft A. Thehollow shaft or sleeve B is designed to be operatively connected by anysuitable means with any desired speed responsive mechanism associatedwith the engine or locomotive, and I have illustrated in Fig. 5mechanism suitable for this purpose.

Referring now in detail to Fig. 5, it will be seen that spindle Acarries the hand 21 and also the pinion. 3|, while the sleeve B on saidspindle A carries the hand 26. Said sleeve B may be suitably connectedwith a speedometer shaft C or the like for movement therewith, or withany other suitable instrument indicative of surface speed ormiles-per-hour of the locomotive. The hand 26, moving in agreement witha speedometer shaft C or the like, will indicate on the dial 25 thesurface speed or miles-per-hour, and its operation will be entirelyindependent of the operation of hand 21. The cam 22 is represented asmounted on the shaft C which carries sprocket gear D, and a transmissionchain E is shown as connecting this sprocket gear D with a similar gearF on the sleeve B. By this arrangement, the integrating cam 22, as wellas the hand 26, is operated from, and in agreement with, the operationof the shaft C of a speedometer S or other suitable surface speedindicating instrument. Said modifying cam 22 also constitutes one of thefactors or components for operating the hand 21, as previously stated.

The instrument K is further provided with a second dial indicated at 28in Fig. 2 which is The opposite end of the lever I l calibrated inpercent of maximum piston pull. This dial is arranged with a centralcalibration 29 which indicates the 100 percent point on the scale,-indicating that steam chest pressure, piston speed and cut-off are allproperly positioned to reproduce the maximum results corresponding toefiective piston pull as shown by the curves 6 or I in Fig. 3. Themovement of the hand 21 from such 100% position in a clockwise directioncooperates with that portion of the scale calibrated in percentages lessthan 100 percent and which portion is indicated by a minus sign, whereasthe movement of the hand 2'! in a counterclockwise direction from thesuch 100% position cooperates with that portionof the scale calibratedin percentages less than 100 percent and indicated by a plus sign. Thus,as will be presently explained, the position of the hand 21 on the plusside of the scale will indicate that more steam is being used than theboiler of the locomotive is capable of constantly supplying because thecut-off is too long for the prevailing speed, whereas, when the hand ison the minus side of the scale it will indicate that less than theamount of steam for the most efiicient operation is being used becausethe cut-oif is too short and that less horse power is being producedthan that available within the capacity of the boiler for the prevailingspeed.

In order that the maximum effective piston pull, the steam chestpressure and the speed factor may be permanently recorded during the runof the locomotive, a suitably graduated tape, a part of which isindicated at32, may be provided on a continuously rotating drum (notshown). The part I2 has formed thereon a rack portion .30 in mesh withthe pinion 3! on shaft A, and said part l2 above its rack portion isprovided with a suitable marker 33 adapted to engage on one part of thetape 32. The sleeve B which carries the hand 26 may control means foroperating a movable part 34 furnished with a marker 35 adapted to engageanother part of the tape. The driving connection between the part 34 andthe sleeve B consists of a gear B26 on said sleeve, which gear is inmesh with a rack H34 formed on the part 34.

Similarly, I may provide suitable means for indicating variations insteam chest pressure on the tape, and-to this end I provide the free endof the rod [8 with a rack |8a with which is engaged a gear 36a on ashaft 36 which is mounted for rotation in suitable bearings 36'. Saidshaft 36 has a second gear 3'! and this is engaged with a rack 31acarried by a part 31 which is provided with a marker 38 adapted toengage another part of the tape 32. Therefore, under this arrangement,in addition to indicating the speed and percent of maximum piston by thehands 26 and 21, respectively, of the instrument K, I may provide a tape32 on which to make a permanent record of variations in speed, steamchest pressure and percent of maximum torque.

The eccentric cam 22, which is driven in response to variations in speedof the locomotive pistons as hereinbefore described, has a combiningfunction as shown in detail in Fig. 6. This cam is so shaped that as thepiston speed increases, its point of cam contact with the rollerthereof, if represented by 100 percent on the base a line of maximumpiston pull (Fig. 3) will have a constant value until through radialmovement of the camsuch representative portion has passed through an areequivalent to a change in piston speed from zero to 250 ,feet perminute, at which point, represented on'the cam by the radial line I, thedrop-oil or rescission begins to change to correspond with either of thecurvedlines 6 or 1 (Fig. 3) according to the character of the steam,whether saturated or superheated. when the actual movement of the cambecomes equivalent, for instance, to; a piston speed of 600 feet perminute, as represented by radial line 9 on the cam, then the radialthrow of the cam will become the equivalent of approximately 67 percentof the 100 percent piston pull position, as can be noted in Fig. 3.Again, for example, when the actual movement .of the cam becomesequivalent to piston speed of 1500 feet per minute, as

., represented by radial line hon the cam, its

throw will be approximately 26 percent of percent for line 1, orapproximately 29 percent of 100 percent for line 6. When the cammovement becomes the equivalent of 2,000 feet of piston speed perminute, as represented by radial line i onthe cam, the capacity of theengine will have been exceeded on account of the. stresses ordinarilyset up in the reciprocating parts thereof. It will be understood thatwhen the 1000- motive is at rest or whenever the speed is zero the cam22 occupies a position such that the point on its contour farthestremoved from its center of rotation is pointed downwardly as shown inFig. 6, with the result that the rod 23 is urged downwardly'to itslowest position.

Having thus described my apparatus, I will now indicate'how it functionsto improve the general operating conditions of the engine. In general,and in the absence of indicating instrumentalities such as I have justdescribed, the engineer in starting the engine usually thrusts thereverse lever to its extreme forward or rearward position (dependingupon whether the locomotive is to be driven forwardly or rearwardly) andthen opens the throttle to feed steam to the steam chest. As the enginespeeds up the cut-01f is shortened by gradually moving the reverse levertoward its neutral position and to an extent depending upon the pistonspeed of the locomotive and 'so that the engine will use steam at themaximum rate permitted by the boiler capacity. As hereinbefore stated,dueto the absence of. any means for properly indicating when the reverselever is, positioned to give the proper rate of steam consumption withrespect to existing conditions of piston speed, ideal operatingconditions are seldom, if ever, realized.

The operation of anv engine equipped with my apparatus as thus describedis as follows:

As shown in Fig. 1, with the engine at restand the throttle closed thespeed hand 26 is, of course, on zero at the extreme left hand side ofthe scale 25, while the hand 21 is on the extreme right hand minus sideof the scale due to the fact that the rod i8 is at its extreme lowerposition and the rod i0 is raised to its higher position. Furthermore,the position of the rod 23 in its lowest position due to zero speed,positions the hand 21 to the extreme right hand portion of the dial. Todrive the engine forwardly the reverse lever is first thrust to, itsextreme forward position, and this causes movement of the rod l0downwardly to its lowest point, which correspondingly moves the hand 21in a counterclockwise position toward the 100 percent mark 29. Thethrottle is then opened to admit steam to the steam chest and thispressure operating upon the'piston it moves the rod l8 upwardly and thismovement is instrumental in further shifting the hand 21 in acounterclockwise direction to the 100 percent mark. The

engine now begins to move and as it picks up speed beyond the pointindicated by X on the curves 6' M1 of Fig. 3, the cam 22, moving inresponse to such increase, shifts to allow the rod 23 to move-upwardlyunder the tension of the spring I23, which movement is reflected byfurther movement of the hand 21 in a counterclockwise direction, thuscarrying said hand more and more away from the 100 percent mark 29 onthe plus side of the scale. This indicates to the engineer that theprevailing position of the cut-off is too long for the prevailing speed,and, accordingly, the cut-off is shortened by moving the reverse levertowards its neutral position, which operation is reflected by an upwardmovement of the rod I0 and a clockwise movement of the hand 21. Thus,the reverse lever is operated in response to changes in the speed tomaintain the hand 21 as nearly as possible on the 100 percent mark 29 atall times in order that the engine will give the percent of maximumavailable piston pull. If it is desired to operate under conditions ofmaximum efliciency with regard to steam consumption, the cut-01f ismanipulated to maintain the hand 21 over as far as possible on the minusside of the scale, and this condition of maximum em ciency can beaccomplished only by operating under shortest possible cut-01f.Fluctuations in steam pressure will, of course, be reflected directly inspeed variations so that variations in either or both of these factorswill be evidenced by movement of hand 21' clockwise for falling speed,for falling steam pressure, or both and counterclockwise by risingspeed, by rising steam pressure, or both. Thus the instrument K keepsthe engineer constantly apprised by the position of hand 21 on the scale28, giving thereby a visual indication of existing operating conditions,with reference to prevailing speed, steam pressure, and cut-oflf, bywhich the engineer may efiectively adjust the reverse lever to properlyset the cut-off valve to distribute the steam at the most economicaleffective rate. In this way the maximum 7 available effort of the engineat a particular speed, without causing a drain on the boiler, can

be realized. At the same time the engineer may be apprised of thelocomotive speed by referring to hand 26.

In contrast to Fig. l where I illustrate the rods in, I8, and 23 and thehands 26 and 21, in the relative positions which they may assume whenthe engine is at rest, Fig. '1 shows the same parts in the relativepositions which they may respectively assume when the engine is movingapproximately at the rate of sixty miles per hour under correct steampressure control. In Fig. '7, it will be seen that the reverse lever 50has been moved to an intermediate position towards neutral from its fullforward throw of 100 per cent open position, and this of course meansthat the cut-off line -5! denotes a piston speed of about 1307 feet perminute, and this piston speed, when translated into terms ofmiles-per-hour, means that the locomotive is traveling approximately atthe. rate of 60 miles per hour, as will presently appear. In Fig. 7, thehand 26 is pointing to the 60 miles-per-hour notation on the dial 25,indicating thereby the locomotive speed, while the hand 21 is pointingto the maximum 100 per cent piston pull notation on dial 28, indicatingthereby that the cut-off is in proper position for the prevailing 60miles-per-hour speed. I

Speed effect is usually graduated in miles-perhour, the speed formula atthe rate of.60 miles per hour being, per minute mile,

feet, or its equivalent 1056 (88x12) inches. It is of course well knownthat piston speed is twice the piston stroke multiplied by the completenumber of cycles per minute. Assuming that the each revolution of thedrivers under 56-inch piston travel is feet, which is the piston speedof the engine when traveling at the rate of 60 miles per hour.

Referring now to Figs. 5, 6, and 7, the cam 22 will be turned by thespeed mechanism to a point corresponding with this piston speed asillustrated by the line c-g' which is equivalent, as shown by the hand26 on the dial 25, to 60 miles per hour.

From the foregoing it will be obvious that each change in therelationship between piston stroke and driving-wheel diameter willnecessitate a new determination of the cam stroke and angles in orderthat speed in miles per hour will be converted into piston speed in feetper minute. As hereinbefore explained, it is to be understood that theuse of the hand 26 and its accompanying dial 25 is entirely immaterialto the use and operation of this invention, said hand and dial beingshown herein only for the purpose of demonstrating more fully how thecam functioning as the speed element, is one of the three variablefactors, namely, pressure, piston speed and position of the controlvalve. As previously pointed out the actions of these three variablesare consolidated into a single result or effect which is made known tothe engineer by the movement of the hand 21 over the dial 28.

When the hand 21 movesover the plus side of the dial from the 100 percent point, such movement is a certain indication that the cut-off istoo long for the prevailing speed and hence that steam is being wasted.When this hand moves over the minus side of the dial from the 100 percent point, such movement is a certain indication that the cut-off istoo short for the prevailing speed and that more steam may be-usedwithout waste. The hand 2'! always moves clockwise or to the right forfalling steam pressure, for falling speed, or both, indicating that thecut-off should be lengthened; and said hand always movescounterclockwise or to the left for rising steam pressure, for risingspeed, or both, indicating that the cut-off should be shortened. Thecontrol calibration 29 represents the 100 per cent efficiency positionfor the hand 21; that is to say, the maximum piston pull at boilercapacity without waste at a prevailing speed.

Referring to Fig. 4, wherein I have illustrated a set of typical curvesor graphic records of engine operation as inscribed on the tape 32 bythe markers 33, 35, and 38, curve 4! shows possible variations in speed;curve 40 shows the variations in 100 percent of maximum available pistonpullbeing developed, and curve 39 shows variations in the pressure. Thevarious events, as depicted in these several curves, are also shown, asfor instance, the part 4| on curve 4| will represent that zero speed issupplied in curve 40 by the zero point 40. Likewise, the point 41] incurve 40 indicates that the cut-off was shunted to move hand 2'! fromone side of the scale to the reverse side thereof, and this is evidencedby the preceding and successive portions of this curve, occupying aposition off base and below the 100 percent line 33. The drop in steampressure is responsible for the drop 39 in curve 39. With regard to Fig.4 it is desired to state that the driving speed marked on the record isindependent of other markings, and that as to the individual mechanismfor producing the driving speed marking I claim no invention, thisparticular marking and the mechanism for producing the same being shownand described only for the purpose of pointing out a further use of theapparatus that may be conveniently made at a slight extra'cost.

This invention does not in any way apply to devices pertaining tocylinder performance and cannot be used to obtain data necessary for thestudy of steam expansion or efficiency.

In conclusion, therefore, it is apparent that by the method andapparatus herein described, I convert variations in position in cut-off,steam pressure and tractive force as influenced by piston speed, intoforces which I combine and resolve into a single resultant force whichis applied to actuate an indicating element in response to variations insaid resultant force,

whereby to constantly apprise the engineer of conditions under which theengine is operating, so that he may, by adjustment of the cut-off inaccordance with said indication, insure proper and efficient operationof the engine at all times.

I claim;-

1. In combination, an engine indicator including a movable indicatingelement, means for indicatively moving said element and means foractuating said element moving means including 'a lever pivotedintermediate its ends, said lever at one end being connected to saidactuating means and at its other end being provided with means forconnection to the valve control for the propulsion medium of the engine,means movable in response to variations in pressure of steam supplied tothe engine, and means movable in response to variations in enginedriving piston pull as influenced by piston speed thereof, saidactuating means also including an operative connection between theelement moving means and said means movable .in response to variationsin steam pressure, and .an operating connection between the elementmoving means and the means movable in response to variations in enginedriving piston pull, whereby the 2. In combination, an engine indicatorincluding a movable indicating element, means for indicatively movingsaid element and means for actuating said element moving means includingmeans for operatively connecting the moving means to the valve cut-offadjusting mechanism of the engine for movement thereby, means movinpressure of able in response to variation steam supplied to the engine,and means movable in response to variations in engine driving pistonpull as influenced by piston speed, a lever pivoted intermediate itsends, one end of said lever being operatively connected to the meansmovable in response to pressure variations, the opposite end of saidleveri being connected to the means movable in response to variations inengine driving piston pull, and means for transmitting movements of saidlever to said actuating means for the indicating element whereby thevariations in the position of cut-oil, in steam pressure, and drivingpiston pull as influenced by piston speed-are combined to give a singleindication.

3. In combination, an engine indicator including a movable indicatingelement, means for indicatively moving said ;e1eme nt and means foractuating said element moving means including a lever pivotedintermediate its ends, said lever at one end being connected to. saidactuating means and at its other end being provided with means forconnection to the valve control for the propulsion medium of' theengine, means movable in response to variations in pressure of steamsupplied to the engine, and means movable in response to variationsin'engine driving piston pull as influenced by piston speed thereof, alever pivoted intermediate its ends, one end of said lever beingoperatively connected to the means movable in response to pressurevariations, the opposite end of said lever being connected to the meansmovable in response to variations in engine driving piston pull, andmeans for transmitting movement of the second mentioned lever to thefirst-mentioned lever, whereby the variations in the position of cut-oiTin steam pressure, and in driving piston pull as influenced by pistonspeed are combined to give a single indication.

4. In combination, an engine indicator including. a movable indicatingelement, means for indicatively moving said element and means foractuating said element moving means including a lever pivotedintermediate its ends, said lever at one end being connected to saidactuating means and at its other end being provided with means forconnection to the valve control for the propulsion medium of the engine,means movable in response to'variations in pressure of steam supplied tothe, engine, and means movable in response to variations in enginedriving piston pull as influenced by piston speed thereof, a leverpivoted intermediate its ends, one end of said lever beingoperativelyconnected to the means movable in response to pressure variations,

75 by to move the same in unison in accordance with the relativemovement of said levers, whereby the variations in the position ofcut-ofi, in steam pressure, and in driving piston pull as influenced bypiston speed are combined to give a single indication.

5. In combination, an engine indicator including a movable indicatingelement, means for indicatively moving said element and means foractuating said element moving means including means for operativelyconnecting the moving means to the valve cut-ofi adjusting mechanism orthe engine for movement thereby, means movable in response to variationsin pressure of steam supplied to the engine, and means movable inresponse to variations in engine driving piston pull as influenced bypiston speed of operation thereof, said actuating means alsoincluding anoperative connection between the element moving means and said meansmovable in response to variations in steam pressure, and an operatingconnection between the element moving means and the means movable inresponse to variations f in engine driving whereby the position of theindicating element is modified by the valve cut-oil. adjusting mechanismto compensate for variations in the driving piston pull and in steampressure.

6. The method of indicating locomotive operation comprising convertingvariations in position of cut-ofl, in steam pressure and in tractiveforce as influenced by piston speed into forces varying, respectively,in magnitude and direction in accordance with the efiect such variationshave toward increasing or decreasing thev horse power output of thelocomotive; combining said forces into a single force varying inmagnitude and direction in accordance with the resultant eflect of allof said variations upon the horse power output of the locomotive, andindicating variations in the horse power output of the locomotive inresponse to variations in magnitude and direction of said resultantforce.

7. The method of indicating locomotive. operation comprising reproducingvariations in position of cut-ofl, in steam pressure, and in tractiveforce as influenced by piston speed, respectively,

by movement of control media from one position to another; combiningboth as to direction and magnitude the relative movements of said mediain accordance with the eflect said respective variations have towardincreasing or decreasing the horse power output of the locomotive;reproducing variations in the cumulative efiect of said variations asthus integrated by movement of a single'control element in accordancewith the resultant efiect said variations have toward increasing anddecreasing horse power output of the locomotive; and indicatingvariations in the horse power output of the locomotive due to theresultant effect of said' individual variations in response tovariations in position of said single control element.

8. Resultant means for indicating the performance of a steam engine interms of percent of maximum available piston pull, the engine comprisinga propulsion medium valve control means, steam pressure responsive meansand driving piston pull responsive means responsive to the piston speedof the engine, a movable indicating element and its percentagecalibrated maximum available piston pull dial, connections connectingthe indicating element with the valve control means and the steampressure responsive means whereby variations in the operation of each ofsaid means are resultant into and efiect the movement or said element ineither direction with respect to its calibrated dial, and a connectioninterconnecting the drivingpiston pull responsive means with thefirst-named connections to. combine variations in the operation of thedrivin: pitton pull responsive means into the operation or saidconnections, said drivin: piston pull responsive means and theinterconnections therewith bein: active on and throulh the first namedconnections to eiiect the movement 0! said indicating element reverselyin either direction with respect to the movements thereof caused byeither the valve control means 5 or by the steam pressure responsivemeans.

VIRBI'NIUS Z. CARAORIB'I'I.

